perfSONAR User Q&A and Other Discussion

[David Koski <>]

We've found that all our perfsonar systems are reporting a reverse path loss between them in the graphs - scheduled test (however the forward graph for the same path from the opposite server shows no loss).  We can't find a reason for why this is, and if "feels" like a perfsonar server issue since we have 10 systems doing the same issue.  We are seeing random packet loss that we can't explain (anywhere from consistent 80% loss to random loss between 0 and 100%).

Incidentally, while we haven't been able to confirm that this started from the 3.3 to 3.4.1 upgrades, we did notice that one of the servers did start it's reverse packet loss around the time we upgraded to 3.4.1.

As a couple of items, the servers are configured with multiple interfaces and appear properly setup under 3.4.1 for this.  The hosts are very close together as well (Around 0.3 ms).

Any one have any thoughts or perhaps a way of troubleshooting this?  Forward packet loss is constantly 0 no matter the host, reverse is always some form of packet loss (either consistent or bouncing between 0 and 100).  We haven't seen this issue going from our hosts off our network.

      Thanks

             David

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David Koski

ITS ISO Communications Systems and Data Centers Operations

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